Similar αGal biodistribution with varying the design parameters of anti-ICAM NCs. Mice were injected i.v. with 1.6 x1013 NCs/kg of anti-ICAM/125I-αGal NCs prepared to contain 95:5 or 50:50 antibody-to-enzyme surface-density ratios (52 vs. 524 αGal molec/NC), which rendered low (45 μg/kg) or intermediate (Intm; 449 μg/kg) αGal doses, respectively. In addition, anti-ICAM/125I-αGal NCs displaying 50:50 antibody-to-enzyme surface-density ratios was injected at 2.4×1013 NCs/kg (high αGal dose; 555 μg/kg). Organs were harvested 30 min after injection, weighed, and measured for 125I content to determine (a) percent of total injected αGal dose (%ID) in each organ and (b) relative tissue-to-blood targeting efficiency as %ID αGal per gram of organ (%ID/g) to compare among organs of different size. Data are mean ± SEM; n≥4; *p<0.05, **p<0.01, comparing to low αGal doses by Student’s t-test. Comparing intermediate and high αGal doses rendered p>0.1.